The weight of pure $NaOH$ required to prepare $250 \ cm^3$ of $0.1 \ N$ solution is ......... $g$. (in $g$)

When $100 \, ml$ of $0.1 \, M$ $H_2SO_4$ reacts with $Na_2CO_3$, how many liters of $CO_2$ will be produced at $STP$ (in $L$)?

$CaCO_3$ reacts with $HCl$ to produce $CaCl_2, CO_2$ and $H_2O$. The approximate mass (in $g$) of $CaCO_3$ required to react completely with $25 \ mL$ of $0.75 \ M \ HCl$ is (atomic mass of $Ca=40, C=12, O=16, Cl=35.5$ and $H=1$).

$0.1 \ M$ solution of $KI$ reacts with excess of $H_2SO_4$ and $KIO_3$ solution. According to the equation $5I^{-} + IO_3^{-} + 6H^{+} \rightarrow 3I_2 + 3H_2O$. Identify the correct statements $:$
$(A)$ $200 \ mL$ of $KI$ solution reacts with $0.004 \ mol$ of $KIO_3$.
$(B)$ $200 \ mL$ of $KI$ solution reacts with $0.006 \ mol$ of $H_2SO_4$.
$(C)$ $0.5 \ L$ of $KI$ solution produced $0.005 \ mol$ of $I_2$.
$(D)$ Equivalent weight of $KIO_3$ is equal to $\frac{\text{Molecular weight}}{5}$.
Choose the correct answer from the options given below $:$

If $0.4 \ g$ of $NaOH$ is present in $40 \ mL$ of solution,what will be the molarity and normality? (Molecular weight of $NaOH = 40$)

What is the number of hydrogen molecules needed to synthesize $3.4 \text{ g}$ of ammonia by reaction with nitrogen?